Tuesday, November 27, 2007

Road Testing BMW's Hydrogen 7

Wired magazine succumbs here to the 'Technology Will Save Us' daydream. While no one can fault a car running on hydrogen as a nice innovation, you can throw a few cream cakes at these guys for failing to think a little further: how to set up hydrogen infrastructure into current service station infrastructure.
It's been said that to transport similar amounts of energy, you'd need 21 tanker sized trucks filled with liquid hydrogen for every gasoline truck . Experts have said that the mere raised rate of having so many fuel tankers on the road (IE mobile bombs) negates the practicality involved. The risk would simply be too great, both politically and otherwise. That's the bottom line here: it's just so far from practical as to be absurd.

The automaker's approach is markedly different than the more familiar concept of
hydrogen-powered fuel cells, where energy is stored before it is converted into
electricity. By contrast, BMW's Hydrogen 7 is powered by pumping hydrogen into a
combustion engine and igniting it. The engine can burn both hydrogen and
gasoline, and switches between the two at the flick of a switch.
Burning hydrogen is more efficient than converting it into electricity, making it the more practical choice for hydrogen-fueled cars now, according to BMW.
One major challenge is how to keep the hydrogen cooled to minus 253 degrees Celsius (minus 423 degrees Fahrenheit) so it remains in liquid form without boiling off. Despite the double-walled, stainless-steel tank that stores the liquid in high-vacuum conditions with aluminum reflective foil, the liquid hydrogen in the 8-kilogram fuel tank begins to boil after 17 hours if the car remains parked. The tank empties completely after 10 to 12 days.
Hydrogen ain't an energy source. Sorry. You've got to get it (as in extract it) out of the atmosphere. Generally electricity is used in this process, and the amount of energy required to separate the atoms is just way to energy intensive. Guys, please stop wasting your time on hydrogen. Rather apply energies to developing a plu and play car, or better yet, resuscitate railway and streetcar networks.

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